Abstract
Background: Neutrophilic airway infiltration is central to chronic obstructive pulmonary disease (COPD) pathogenesis. COPD patient sputum contains high levels of neutrophil-derived microvesicles (NMVs). NMVs can be internalised by and activate target cells, however, little is known about their interaction with the lung epithelium.
Methodology: NMVs were isolated from human neutrophils treated with PBS, 10µM fMLP, or 50% cigarette smoke extract (CSE) for 1h. Matrix metalloproteinase-9 (MMP-9) levels were determined by western blotting (n=4). Internalisation of fluorescently-labelled NMVs by BEAS-2B bronchial epithelial cells after 2h was quantified using confocal microscopy and flow cytometry (n=5), and IL-8 and MCP-1 secretion after 24h was quantified by ELISA (n=3).
Plasma MVs from exacerbating COPD patients (n=6) and age-matched controls (n=5) were analysed by multi-colour flow cytometry to determine cellular origin and surface MMP-9 expression.
Results: CSE generated more NMVs than fMLP. NMVs from stimulated cells had high levels of active MMP-9, were internalised by BEAS-2B cells (34.1±15.0%) and significantly increased epithelial IL-8 (>12-fold; p6-fold; p
In patient plasma, NMVs represented 22.5% of the total MVs, and surface expression of MMP-9 was detected (117.4±75.8 MMP-9+NMVs/µl), however, levels did not differ between patients and controls.
Conclusion: NMVs contain proteases associated with COPD progression and induce pro-inflammatory activation of lung epithelial cells, indicating a potential pathogenic role in the disease. Systemic NMV levels may not correlate with levels in the lungs and local production of NMVs may be key.
Footnotes
Cite this article as: European Respiratory Journal 2019; 54: Suppl. 63, PA1669.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2019